title: In vitro and in vivo evidence suggesting a role for iron in cisplatin-induced nephrotoxicity.
abstract: Cisplatin is a widely used antineoplastic agent that has nephrotoxicity as a major side effect. The underlying mechanism of this nephrotoxicity is still not well known. Iron has been implicated to play an important role in several models of tissue injury, presumably through the generation of hydroxyl radicals via the Haber-Weiss reaction or other highly toxic free radicals. In the present study we examined the catalytic iron content and the effect of iron chelators in an in vitro model of cisplatin-induced cytotoxicity in LLC-PK1 cells (renal tubular epithelial cells) and in an in vivo model of cisplatin-induced acute renal failure in rats. Exposure of LLC-PK1 cells to cisplatin resulted in a significant increase in bleomycin-detectable iron (iron capable of catalyzing free radical reactions) released into the medium. Concurrent incubation of LLC-PK1 cells with iron chelators including deferoxamine and 1,10-phenanthroline significantly attenuated cisplatin-induced cytotoxicity as measured by lactate dehydrogenase (LDH) release. Bleomycin-detectable iron content was also markedly increased in the kidney of rats treated with cisplatin. Similarly, administration of deferoxamine in rats provided marked functional (as measured by blood urea nitrogen and creatinine) and histological protection against cisplatin-induced acute renal failure. In a separate study, we examined the role of hydroxyl radical in cisplatin-induced nephrotoxicity. Incubation of LLC-PK1 cells with cisplatin caused an increase in hydroxyl radical formation. Hydroxyl radical scavengers, dimethyl sulfoxide, mannitol and benzoic acid, significantly reduced cisplatin-induced cytotoxicity and, treatment with dimethyl sulfoxide or dimethylthiourea provided significant protection against cisplatin-induced acute renal failure. Taken together, our data strongly support a critical role for iron in mediating tissue injury via hydroxyl radical (or a similar oxidant) in this model of nephrotoxicity.
authors.affiliation: Department of Pediatrics, University of Mississippi Medical Center, Jackson, USA.
authors.forename: R
authors.initials: R
authors.lastname: Baliga
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Baliga
authors.forename: N
authors.initials: N
authors.lastname: Ueda
authors.forename: S V
authors.initials: SV
authors.lastname: Shah
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000378:metabolism; D000818:Animals; D000931:Antidotes / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001806:Blood Urea Nitrogen; D016923:Cell Death / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D002945:Cisplatin / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood; D003603:Cytotoxins / Q000494:pharmacology*; D003676:Deferoxamine / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology; D007501:Iron / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D018374:LLC-PK1 Cells / Q000187:drug effects / Q000201:enzymology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013552:Swine; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000931:Antidotes; D000970:Antineoplastic Agents; D002614:Chelating Agents; D003603:Cytotoxins; D016166:Free Radical Scavengers; C038983:1,3-dimethylthiourea; D003404:Creatinine; D007501:Iron; D007770:L-Lactate Dehydrogenase; D013890:Thiourea; D003676:Deferoxamine; D002945:Cisplatin; D004121:Dimethyl Sulfoxide